LASER: Riskier than you think
I have some academic friends that are fond of reminding me that just because you know a word, you don’t necessarily know what it means. Laser is a good example. We all use the word. When I took college physics, admittedly back in the days of slide rules and log tables, it was a big deal when a laser device the size of a shoe box was brought into lab and shined on the wall. My only previous exposure to lasers was from the movie Goldfinger where Sean Connery was going to be split in two by a laser beam. I learned the meaning of laser, but when the FDA issues a safety alert, I had to go to the dictionary for an accurate definition. Do you know what laser means?
Definition of laser
Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. I didn’t find that particularly helpful. Webster’s Collegiate Dictionary defines laser as “a device that utilizes the natural oscillations of atoms or molecules between energy levels for generating coherent electromagnetic radiation in the ultraviolet, visible of infrared regions of the spectrum.” I hope this definition is more useful to you than it is to me. Actually, it is a great reminder that we are so wrapped up in and conversant about technology that we think we know more than we do. We can become inured to risk. We are inadequately vigilant and lose situational awareness. How many of us use laser pointers, but don’t know the power they emit? What is a safe power level?
The risks of lasers
The FDA reminder points out that most products containing lasers are safe, but some are used as toys. For example, the visible light power of hand-held pointers is limited to 5 milliwatts. Even at this level a laser aimed directly at an eye can cause temporary flash blindness. Reflexes such as blinking or moving the eyes usually have protective effects that decrease the likelihood of permanent injury, but intentionally looking at a laser will cause injury. Some injuries that impair vision are painless. Lasers that emit more than 5 milliwatts of visible light power can cause permanent injury and even burn skin.
The FDA reminds us that laser pointers are not toys. Children should not be allowed to use them. Never buy a pointer that doesn’t have the power printed on it or exceeds 5 milliwatts. Never shine a laser at any person, pet, vehicle, or aircraft. Do not aim a laser at any reflective surface, i.e., a mirror or shiny surface. Any time a laser and an eye make contact, seek immediate medical attention. Remember the injury may be painless. The FDA has found that some labels are misleading.
High powered lasers may be promoted as powerful, bright, ultra, super, military, military grade, super bright, strong, balloon pop, burn, adjustable focus, and lithium powered. If you see these words, the product likely exceeds 5 milliwatts. Safe laser pointers are usually small and use button batteries. If it is the size of a pen or bigger, (like a flashlight) and uses AA or AAA batteries, it is likely too powerful. Avoid laser pointers that have a removable cap that spreads the beam into a pattern. When the cap is removed, the single beam may exceed 5 milliwatts. If laser pointers are advertised in videos or photos that show them burning, melting, or popping balloons. Don’t buy them.
Are there any other devices you use regularly that are dangerous? Think about it.
FDA MedWatch-Hand-held Laser Pointers-Risk of Eye and Skin Injuries. www.fda.gov/MedWatch. Accessed January 13, 2016 at 9:12 am.